Hydromechanical stored-energy spring mechanisms can have differential cylinders. A piston of the differential cylinder is connected to a piston rod, which can be moved by pressurization of a pressure volume. The piston rod can be connected to an electrical circuit breaker, thus enabling the electrical circuit breaker to be switched by moving the piston rod. To open the electrical circuit breaker, for example, the pressure volume of the differential cylinder can be subjected to a hydraulic pressure, moving the piston rod into a corresponding position.
The pressure in the pressure volume can be supplied by a pressure cylinder, which can be coupled to a mechanical energy storage device, for example, a spring arrangement. If the circuit breaker is to be switched, the spring force on the pressure cylinder is released, with the result that a working pressure builds up there. This is also present via a hydraulic connection in the pressure volume of the differential cylinder. The working pressure in the pressure region can move the piston and the piston rod of the differential cylinder.
If the mechanical energy storage device on the pressure cylinder is designed as a spring arrangement, it can be subjected to a preload in order to provide a sufficient force. When the spring arrangement is triggered, the working pressure can build up very quickly, and therefore the pressure region of the differential cylinder can be subjected almost immediately to the working pressure. As a result, the piston of the differential cylinder can be moved in the direction of an end stop with a high acceleration force. To protect the differential cylinder and the other mechanical components coupled thereto, end position damping can be provided, in which the speed of the piston can be reduced before it or some other component strikes a stop. Damping is intended to ensure that the final speed of the piston upon impact is brought below a predetermined threshold in order to avoid damage to the components.
Depending on the application and on the type of circuit breaker to be switched, on the trigger speed, the working pressure provided and the like, a specific geometrical design of the damping can be devised for each individual application. As a result, the hydromechanical stored-energy spring mechanisms can already be tied to a particular use at the beginning of manufacture. It can be difficult to change the area of application after their production. This makes the production of hydromechanical stored-energy spring mechanisms inflexible because they may only be produced specifically for a particular application and it may not be possible to produce them as reserve stock for a number of undefined uses and to adapt them to the given application after their production.
It is therefore desirable to provide a hydromechanical stored-energy spring mechanism which has end position damping that enables retardation in such a way that a final speed of the piston rod below a predetermined threshold is achieved before the piston, the piston rod or a component connected thereto strikes an end stop, irrespective of the working pressure supplied by the mechanical energy storage device and irrespective of the mass moved by the piston rod.